1. Field of the Invention
This invention relates to an injecting unit for use in an injection molding machine, which unit is movable by means of at least one actuating member toward a gate of an injection mold in said machine and comprises a plasticizing cylinder, at least one feeding unit, which is mounted on a feeding block associated with the elasticizing cylinder and is movable on a track rail of the feeding block from a feeding position, in which the plastic material flows from an outlet opening of the feeding unit through a feeding bore of the track rail and a shaft of the feeding block from above into the plasticizing cylinder, to an emptying position, in which the outlet opening of the feeding unit resisters with an emptying bore of the track rail, and at least one injecting member for axially displacing a plasticizing screw in the plasticizing cylinder.
2. Description of the Prior Art
Injecting units of that kind are known from FIG. 4 of DE 29 20 584 C2, from lines 21 to 29 of column 2 and lines 20 to 30 of column 4 of DE 30 46 387 C2 and from the corresponding passages of the corresponding U.S. Pat. No. 4,418,845, and from DE 32 28 161 and the corresponding U.S. Pat. application Ser. No. 518,126, now U.S. Pat. No. 4,629,410. In said known injecting units the track rail for guiding the feeding unit extends transversely to or beside the vertical longitudinal plane of symmetry of the injecting unit so that the emptying bore is outside the vertical projection surface of the injection unit and is thus readily accessible for the receipt of the plastic granules flowing down. But that advantage is afforded only at the expense of a considerable asymmetry of the injecting unit or a large lateral overhang of the feeding unit or of the emptying device. For this reason each of the injecting units disclosed in the printed publications mentioned hereinbefore necessarily involves a different spatial arrangement of the track rail relative to the plane of symmetry of the injecting unit.
Just as in the injecting units of the type described first hereinbefore, it is possible in the feeding unit of a known extruder (German Utility Model 71 48 839) to arrange the outlet opening of one or more hoppers in register with an emptying opening which is spaced from the plane of symmetry of the extruder.